A federal agency that is supposed to protect communities from toxic threats is being accused of using bad science to falsely reassure communities, after it reversed its findings in two recent incidents.

"One of the world's largest nuclear plant suppliers has ordered its Canadian division to hermetically seal itself off from its U.S. parent, going so far as to forbid engineers at the U.S. wing from having anything to do with Canadian reactors."

As the 25th anniversary of the chemical leak in Bhopal, India, approaches, the effects are still painfully present. Thousands were killed immediately; tens or hundreds of thousands were injured in the longer term. It could happen in the U.S.

"President Obama today unveiled key details of the U.S. negotiation position headed into next month's global warming talks in Copenhagen, including a provisional greenhouse gas emissions target for 2020 "in the range of 17 percent below 2005 levels" and a new itinerary that includes a personal appearance during the opening days of the U.N. conference."

"No kid should ever play in arsenic. Especially at school. Yet many probably do, according to findings of a study presented today."